Last month I published hydrophone recording „Crawling glacier“ from the lagoon beneath Svínafellsjökul icefall.
The original recording contains two other channels with the sound above the lagoon.
It is not as clear in this short mp3 file as it is with headphones in the field, but during the recording it seems to be possible to hear the flow of the icefall though the valley. Its is a slow event. It usually starts high above in the mountain with rumbling sound and then slowly moves in a shock wave as a silk smooth „white noise“ though the valley all the way to the toe of the icefall. Regularly the ice moves faster in some places when the pressure get high. Then it cracks, some parts brake off and other just crawl faster which is usually audible for everyone.
This behavior of the glaciers is not often audible during the day because of traffic, wind or the clear sun which can easily disturb the sound waves in the air. Then it is also too slow for impatient listeners. Nights are usually the best time to hear this sound of the „flowing mass“. Changeable nature or different types of glaciers will also play a big rule how it acts and sounds.
Quality open headphones are recommended while listening at low to mid level, or in speakers at medium level.

It is a special feeling to stay close to a glacier. It’s like standing near a wast monster that is constantly moving, but very slowly. Everywhere around this flexible ice the gravity of the ice is visible. Glaciers usually have strong smell of fresh oxygen that glaciers have captured in ice and compressed in to locked bubbles for hundreds and thousands of years. This smell from the past is like from another world, probably because today has much more carbon dioxide in the atmosphere than it has been for 800 thousand years at least. Glaciers also make sounds, sometimes quite loud, from falling drops of water to earthquakes, but most of these sounds are not audible to human ears. Glaciers make constant sound in water which needs hydrophones to capture, as can be heard on the following recording. I can not say I have been lucky in recording glacier sounds in years past. I’ve always been at the wrong place at the wrong time when glaciers produce “big sounds”, but after many hours, and several days on the same spot, I got something interesting which is worth listening to.
One of those days was 5th of June 2015 when I was at the glacier lagoon neneath of Skaftafellsjökull glacier’s icefall. This lagoon is not big, probably around 500m squared, but the depth is around 80 meters so the soundscape beneath the surface can be pretty exhilarating when the glacier is crawling at the bottom of the lagoon.
I put two hydrophones in the lagoon and two microphones on a nearby hill and recorded there for almost fourteen hours. The gain on the recorder was almost equal on all channels, or around 48dB, and during these 14 hour session the soundscape was different mostly because the glacier surface melts differently during the day then during the night with different water flows into the lagoon. All the time the glacier was grinding the bottom of the lagoon so under the lagoon’s surface the soundscape was much nosier than above.
Then just before midnight the glacier did a “big move” (starts 25:00) which lasted for several minutes, crawling with cracking and scratching sound. The soundscape down in the lagoon sounds really strange and surreal, but the listener must keep in mind that sound travels much faster in water than in the air. The soundscape above the lagoon was different. It was possible to ‘feel’ or ‘see’ through the audio the movement of the whole Svínafellsjökull glacier icefall through the valley. But that recording will be for another soundblog.
Quality open headphones are recommended while listening at mid level, or in speakers at medium level.

Vatnajökull is the largest ice cap in Europe by volume (3,100 km³). Vatnajökull has around 30 outlet glaciers (icefall) flowing from the ice cap. Svíafellsjökull is one of them.
Glaciers are not a playground for everyone. They have its own weather system and the gravity force will destroy everything that get lost in the ice.
Two British students lost their lives 1953 in a storm which lasted for 10 days on the glacier. It was not until 2003 that some of their equipment was found, carried forward with the movement of the outlet glacier. No human remains were found.
Two German tourist have been missing since 1st of August 2007 when they were on a hiking trip on Svínafellsjökull. Nobody knows what really happened but it is most likely that they fell in a swallow somewhere on the glacier, but their equipment was found in a small valley, high in the nearby mountains.
All glaciers have been shrinking fast last decade. That can be easily seen at the end of Svínafellsjökull witch now has a big glacier lagoon that did not exist few years ago.
As glaciers the glacier lagoons can be also dangerous. Icebergs can suddenly fall off the icefall and make huge waves in the lagoon, also when icebergs turns around or brake down in a parts.
I got in touch of these forces when I was recording the lagoon under Svínafellsjökull, 23rd of May 2014. I hid the equipment from other tourist in a landslide nearby and about two meters above the lagoon surface. Two Aquarian hydrophones where placed in the lagoon and a pair of MKH20 was used to pick up the sounds above the lagoon. The idea was to record in two or three hours.
I was in another place with my second recorder to record a sound close by the glacier.
After one and half hour I suddenly hear a big „bang“ with a long powerful echo from nearby mountains. All the icebergs on the lagoon suddenly moved around as a beans in a boiling pot.
I ran to the recorder´s place on the other side of the lagoon. The bag with the recorder was floating between the Icebergs so it was no problem to locate it in the muddy water. I disconnect the battery and took it inside to dry it as fast as I could. But nevertheless, it had several malfunctions since this drowning.
I am not sure what really happened. The flood line does´t goes all the away to the recorder´s place. I think it is most likely that some icebergs pulled the recorder by the hydrophones into the lagoon.
Thanks to Sound Devices in US and the reseller in Iceland (Pfaff-Borgarljós and Bragi Kort) I got a new recorder for a very nice price. Most of the loss was then covered by the insurances.